Boiler



(No Model.)

' 2 Sheets-Sheet K. J. PLENTY & J. H. MILLER.

BOILBRI Patented Mar. 3, 1896.

WITNESSES; p INVENTORSx W W' NlTE TATES ATENT FFICE.

JOSEPH PLENTY AND JOHN H. MILLER, OF JERSEY CITY, NEW JERSEY; SAIDMILLER ASSIGNOR TO HENRY BERG, OF ORANGE, NEW JERSEY.

BOILER.

SPECIFICATION forming part of Letters Patent No. 555,880, dated March 3,1896. Application filed May 20, 1895. Serial No. 549,885. (No model.)

To all whom it may concern.-

Be it known that we, JOSEPH PLENTY and JOHN H. MILLER, citizens of theUnited States, residing at Jersey City, in the county of En dson andState of New Jersey, have invented area of heating-surface, with aconstruction and assemblage of parts which shall be compact andeconomical to build.

The boiler is of the double tubular type, in which the water or steam isconfined in the space between the inner and the outer tubes, the heatand products of combustion from the furnace passing around the outertubes and through the inner tubes.

The invention consists of an arrangement of tubes and diaphragms withrespect to the fire-chamber whereby a compact structure is obtained andthe heat is economically dis tributed.

The invention also consists of the specific construction of the tubes.

Referring to the drawings, Figure 1 is a ver tical central section ofthe boiler. Fig. 2 is a horizontal half-section of the boiler, taken onlinew m of Fig. 1. Fig. 3 is a section taken on line y y of Fig. 1, withparts broken away; and Figs. 4 and 5 show the tubes in detail.

It being the intention to construct a portable boiler, the inclosin gwalls will be of sheet metal; but the invention claimed herein is notlimited to an apparatus so constructed. Referring to the drawings byletter, A represents the fire-chamber, a the grate-bars, and a thefire-door. The rear wall of the firechamber is a metal plate ordiaphragm b rising to a point about one-half the distance to the dome ortop of the structure. A short distance in front of the rear wall, I), welocate a second vertical diaphragm b A space is left beneath the loweredge of this, but it extends entirely to the top of the structure.Across the front of the boiler, a short distance back of the front wall,11 we locate another Vertical diaphragm 19 This rises from a point abovethe fire-door to a point within a short distance of the top plate 11 ofthe structure. Another, diaphragm b is arranged horizontally from theupper edge of diaphragm b to the diaphragm 12 The space between theouter walls and the three diaphragms b 1), and bconstitutedraft-passages, to be hereinafter more particularly referredto. The upper portion of diaphragm N, which separates the verticaldraft-passage from the horizontal draft-passage, is provided withopenings b (Shown in Fig. 3.)

Two sets of tubes 0 and C, respectively, are used. The former are abouttwice the length of the latter and occupy the upper part of thestructure below diaphragm I). Tubes C occupy the lower part of thestructure and extend from diaphragm b to diaphragm b being supported bysaid diaphragms. Each tube is dup1ex,consisting of an external tube, 0,and an internal tube, 0. In the set C the tubes 0 establishcommunication between the vertical draft-passages at the rear and frontof the structure, and in the set 0 the tubes 0' establish communicationbetween the fire-chamber and the vertical passage at the rear of thestructure. The outer tubes, 0, in both instances are exposed externallyto the heat from the fire-chamber, which first rises vertically, thenpasses rearwardly over the top of diaphragm Z), thence downwardly andunder the lower edge of diaphragm b thence upwardly through thedraft-passage at the rear of the structure, thence forwardly through thetubes 0 of the set 0 to the vertical passage in the front part of thestructure, and thence out through the chimneyD. A portion of the heatfrom the rear vertical passage also passes through the openings 19 andleads thence forward over the horizontal diaphragm b to the chimney.

The tubes are arranged in horizontal rows,

those of each row being connected together at their ends bycross-passages e. These passages connect together the water or steamspace of each double tube. The cross-passages at the rear connect ateach extremity, by means of elbows c, with a vertical tube f, whichrises to an upper corner of the structure and leads thence to a largecentral steam or hot-water drum F by means of a cross-pipe f. Thecross-passages at the forward end of the set of tubes 0 connect in asimilar manner With vertical pipes g, which also rise to the upper partof the structure and there connect with the drum F. The lower ends ofvertical tubes f connect respectively with single horizontal tubes 71,which lead forward and flank each side of the fire-chamber in the lowercorners thereof. The lower ends of pipes 9 connect in similar mannerwith single horizontal tubes 2', flanking the fire-chamber at the uppercorners thereof, but extending only to the diaphragm b. The tubes ordrums t and h are connected together by a series of vertical tubes j,all of which are subjected to the heat from the fire-chamber. Thecrosspassages connecting the forward ends of the set of tubes G leadinto short vertical pipes 70, which connect at their lowerendsrespeetively with the two pipes h. Cold water is admitted to thepipes 7t through the plugs h, and hot water or steam is taken from theboiler through either or all of the plugs min the drum F.

A feature of the invention is the construction and assemblage of theduplex tubes. The inner and outer tubes are connected together at theirends by heads or couplings o. The coupling at one end has an opening 0,which the outer tube screws into. Opposite this opening and upon thesame axis is another opening 0"*, which the end of the inner tube fits.the tubes has an opening 0 fitting the outer tube, and opposite it uponthe same axis another opening 0 somewhat larger than the end of theinner tube. The parts are assembled by first screwing the two couplingsonto the ends of the outer tube. The inner tube is then passed throughopening 0 until it reaches opening 0 at the other end, when it isscrewed into place therein. This tube is then secured by means ofan-interiorly and exteriorly threaded bushing or nut 19, the outerthread of which fits opening 0 and the inner thread the tube. This nut13 is provided with a shoulder 12, between which and the coupling 0 thetube-sheet or diaphragm in the boiler maybe clamped, as indicated in Thecoupling at the other end of.

Figs. 1 and 2 of the drawings. The crosspassages connecting thehorizontal rows of tubes together are formed by short lengths of pipe q.These are threaded at each end and screwed into openings q in the sidesof the coupling.

Having thus described our invention, we claim- 1. In a steam orhot-water boiler, the combination of a fire-chamber, two sets of duplextubes, one longer than the other, three vertical parallel diaphragms, adraft-passage be yond each of the outer diaphragms and passages for theproducts of combustion, leading from the fire-chamber around theexterior of both sets of tubes, and through the shorter set of tubes tothe passage beyond one of the outer diaphragms, then joining and leadingtogether through the longer set of tubes, substantially as described.

2. In a steam or hot-water boiler, the combination of three verticalparallel diaphragms, draft-passages arranged beyond the outerdiaphragms, two sets of tubes, one set extending between the outerdiaphragms, and the other extendin gbetween the intermediate diaphragmand one of the outer diaphragms, a fire-chamber between an outer and theintcrmediate diaphragm, the draft from which J OS. PLENTY. JOHN H.MILLER. \Vitnesses:

MILEs MoCARnoN, JOHN KRAEGER.

